Chemical Groups Research Articles

Effects of hexagonal boron nitride nanosheets on the biostabilization of recycled sands for geotechnical fill applications

Biostabilization techniques including plant enzyme induced calcite precipitation (EICP) and microbially induced calcite precipitation (MICP) represent promising and environmentally friendly methods for improving the engineering properties of recycled geomaterials for geotechnical fill applications. In this study, hexagonal boron nitride (h-BN) nanosheets were dispersed and utilized as nano-additives in the EICP and MICP reaction processes to facilitate the precipitation of calcium carbonate polymorphs (CaCO3) in washed recycled sands (RS) derived from construction and demolition (C&D) wastes for geotechnical fill applications. The investigation comprised a systematic range of biological and chemical microscopic and macroscopic experiments intending to stabilize the RS for geotechnical fill applications. The study results suggested that using h-BN nanosheets did not have a notable impact on bacterial growth or the functioning of bacterial and plant enzyme activity. In addition, it was observed that the optimal addition of h-BN nanosheet additives substantially increased CaCO3 precipitation by up to 34 % and 28 % in the EICP and MICP reaction processes respectively, which can be postulated to be due to the nanosheets acting as nucleation sites throughout the high surface area and negatively surface charge. Furthermore, the introduction of h-BN nanosheets led to a significant enhancement in the performance of unconfined compressive strength (UCS) of the stabilized RS through nanofillers and reinforcements, with improvements of up to 20 % and 13 % in the biostabilization of RS using the EICP and MICP after 10 treatment cycles. Detailed analyses, including Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) imaging, revealed that h-BN nanosheets, with a substantial surface area and effective chemical functional groups, interconnected with the CaCO3 mineral surface. Overall, the study suggests that integrating effective additives can improve the utilization of EICP and MICP in geotechnical fill applications, namely in road embankments and pavements, whilst providing both commercial viability and enhanced performance.

Evaluation of per- and polyfluoroalkyl substances (PFAS) toxic effects on the acute inflammatory response in the medicinal leech Hirudoverbana

Per- and polyfluoroalkyl (PFAS) substances are a large group of chemicals with elevated water and oil-resistance properties, widely implicated in various applicative fields. Due to the extensive use and high resistance to degradative factors, these compounds pose a significant risk of environmental spreading, bioaccumulating also in living organisms. In this context, despite many researches have been performed to demonstrate “legacy” PFAS harmfulness, only few data are still available about all the emerging fluorinated molecules, industrially introduced to replace the previous ones. For this reason, we proposed the medicinal leech Hirudo verbana as consolidated invertebrate model to assess the effects of four different PFAS (HFPO-DA, PFMoBa, PFOA and PFMOPrA) following freshwater dispersion. Morphological, immunohistochemical and molecular analyses demonstrate that, despite all the compounds basically induce an acute inflammatory and oxidative stress response, a different cellular and molecular response has been observed. Whereas for PFOA and PFMOPrA an increase in the tested concentration leads to a corresponding rise in the immune response, HFPO-DA and PFMoBa trigger an entirely opposite effect. Indeed, the significant recruitment of both granulocytes and macrophage like cells, typically involved in the removal of non-self, is inhibited with increasing concentrations of these compounds. The data collected revealed a different sensitivity of the leech immune system following PFAS exposure, requiring to deepen the current knowledge on the potential toxicity of these compounds.

Sulfated polysaccharide extracted from the alga Gracilaria domingensis modified with propionic anhydride negatively modulates acute inflammation and experimental hypernociception

Sulfated polysaccharides (PLSs) from marine algae represent a broad class of compounds with pharmacological interest, due to their therapeutic properties. PLSs have hydrophilic chains containing various chemical groups of several compositions that differ structurally and in their physicochemical and biological effects. However, this hydrophilic nature of PLSs is also responsible for some limitations in the use of these compounds. To overcome these disadvantages, PLSs can be chemically modified by grafting groups that can give the compound a more hydrophobic nature. In the present study, the PLS from Gracilaria domingensis was modified with propionic anhydride (PLS-AP) and underwent complementary characterizations by scanning electron microscopy, X-ray diffraction, infrared spectral analysis and elemental analysis. The reaction with propionic anhydride increased crystallinity and produced a chemically modified polysaccharide with new carbon, hydrogen and sulfur groups. The new characteristic of the compound may have added interesting properties to PLS, such as increased stability, amphiphilic nature and increased sulfate content, which in red marine algae SPSs produce biological activity. Regarding biological properties, PLS-AP (2.5 mg/kg) significantly reduced paw edema induced by carrageenan, histamine, serotonin, bradykinin and prostaglandin E2, as well as improved microscopic tissue damage criteria. The modified compound was also able to significantly decrease neutrophil migration, myeloperoxidase, and malondialdehyde concentrations and preserved glutathione levels in peritoneal fluid during induced peritonitis. Additionally, in antinociceptive tests, PLS-AP reduced the number of contortions induced by acetic acid and the response time to formalin-induced paw licking. Thus, PLS-AP may be a promising substance to treat inflammatory conditions.

Influence of manufacturing parameters on bioactive glass 45S5: Structural analysis and applications in bone tissue engineering

Bioactive glass (BG-45S5) production through the melting process is affected by a wide variety of parameters. This study investigated the synthesis of BG-45S5 granules and the process variables to produce a bioactive and osteoinductive BG for bone grafting applications. The melting process was initially analyzed by varying parameters such as crucible type and pouring environment using P2O5 as phosphorus precursor. The obtained products were characterized by crystalline phases, characteristic chemical groups, particle size distribution, and chemical composition. Materials poured into graphite or steel molds resulted in particle sizes more suitable for applications in granular form. Using a platinum crucible yielded a chemical composition closer to the target when compared with another ceramic crucible. Subsequently, the melting process was evaluated to different phosphorus precursor (P2O5 or Na2HPO4) and melting duration (1 or 2 h) in a platinum crucible verifying their effects on the thermal behavior, chemical composition and structure of BG-45S5. Employing Na2HPO4 as a precursor led to higher glass transition and crystallization temperatures as compared to P2O5, enhancing glass homogeneity and structural stability. The product with better characteristics in terms of composition and structure was further characterized for bioactivity and cell culture behavior, showing a greater amount of mineralization nodules when compared to commercial hydroxyapatite. This is particularly due to its behavior as the solubility and interaction in biological environments.

The potassium storage performance of carbon nanosheets derived from heavy oils

As by-products of petroleum refining, heavy oils are characterized by a high carbon content, low cost and great variability, making them competitive precursors for the anodes of potassium ion batteries (PIBs). However, the relationship between heavy oil composition and potassium storage performance remains unclear. Using heavy oils containing distinct chemical groups as the carbon source, namely fluid catalytic cracking slurry (FCCS), petroleum asphalt (PA) and deoiled asphalt (DOA), three carbon nanosheets (CNS) were prepared through a molten salt method, and used as the anodes for PIBs. The composition of the heavy oil determines the lamellar thicknesses, sp3-C/sp2-C ratio and defect concentration, thereby affecting the potassium storage performance. The high content of aromatic hydrocarbons and moderate amount of heavy component moieties in FCCS produce carbon nanosheets (CNS-FCCS) that have a smaller layer thickness, larger interlayer spacing (0.372 nm), and increased number of folds than in CNS derived from the other three precursors. These features give it faster charge/ion transfer, more potassium storage sites and better reaction kinetics. CNS-FCCS has a remarkable K+ storage capacity (248.7 mAh g−1 after 100 cycles at 0.1 A g−1), long cycle lifespan (190.8 mAh g−1 after 800 cycles at 1.0 A g−1) and excellent rate capability, ranking it among the best materials for this application. This work sheds light on the influence of heavy oil composition on carbon structure and electrochemical performance, and provides guidance for the design and development of advanced heavy oil-derived carbon electrodes for PIBs.

Synthesis and Characterization of Ester Derivatives of N-Phenylanthranilic Acid

N-Phenylanthranilic acid (fenamic acid) serves as the fundamental structure for synthesizing several non-steroidal anti-inflammatory drugs, antibacterial drugs and also functions as a modulator of membrane transport. To reduce the dose-related side effects of existing drugs, research is focussing to improve fenamic acid derivative solubility and bioavailability. A series of ester derivatives of N-phenylanthranilic acid (MB-1 to MB-5) viz. 2-(phenyl amino)methyl benzoate, 2-(phenyl amino)ethyl benzoate, 2-(phenyl amino)isopropyl benzoate,2-(phenyl amino)butyl benzoate and 2-(phenyl amino)phenyl benzoate were synthesized. The chemical structures and functional groups of these derivatives were confirmed using elemental analysis and spectral data. Furthermore, the derived compounds were evaluated for their antibacterial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) strains using the agar-well diffusion method followed by molecular docking studies to predict binding interactions of the synthesized compounds with DNA gyrase.

Antibacterial and Cell-Viability of Hydroxyapatite Derived from Waste Marine Shell for Biomedical Applications

The present study discusses on the functional groups, structural characterization and thermal behaviour of Crassostrea angulata shell used for the synthesis of a biocompatible hydroxyapatite material. The hydroxyapatite was synthesized from C. angulata shell through precipitation method and characterized using XRD, FTIR, FE-SEM, EDX mapping, HR-TEM and SAED pattern. The formation of hydroxyapatite was confirmed from the high intense X-ray diffraction lines and by the presence of chemical groups such as PO43–, OH– and CO32–. The structural changes during the formation of hydroxyapatite from the thermal decomposition of C. angulata shell were studied through XRD and TG-DTA. The morphology study by FE-SEM indicates that the synthesized hydroxyapatite materials were in the form of clusters of rod-like particles. The SAED patterns and XRD spectral lines confirmed the crystalline nature of the synthesized hydroxyapatite. The antibacterial activity and cell viability assay of prepared hydroxyapatite were studied to assess its suitability in various biomedical applications. The antibacterial activity of hydroxyapatite was assessed against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus saprophyticus) bacterial strains. The cytocompatibility of hydroxyapatite was assessed through an MTT assay using osteoblast cells (MG-63 cell). Thus, the prepared hydroxyapatite shows good antibacterial action and cell viability nature and it can be applied in various biomedical applications.

A comprehensive study on the autochthonous microbiota, volatilome, physico-chemical, and morpho-textural features of Montenegrin Njeguški cheese

The present study aims to deepen the knowledge of the microbiota, gross composition, physico-chemical and morpho-textural features, biogenic amines content and volatilome of Njeguški cheese, one of the most popular indigenous cheeses produced in Montenegro. Cheese samples were collected in duplicate from three different batches produced by three Montenegrin artisan producers. For the first time, the microbiota of Njeguški cheese was investigated using both culture-dependent techniques and metagenomic analysis. Coagulase positive staphylococci viable counts were below the detection limit of the analysis (<1 log cfu g−1). Salmonella spp., Listeria monocytogenes and staphylococcal enterotoxins were absent. However, relatively high viable counts of Enterobacteriaceae, Escherichia coli, Pseudomonadaceae and eumycetes were detected. Metataxonomic analysis revealed a core microbiome composed of Lactococcus lactis, Streptococcus thermophilus, Debaryomyces hansenii, and Kluyveromyces marxianus. Furthermore, the detection of opportunistic pathogenic yeasts such as Magnusiomyces capitatus and Wickerhamiella pararugosa, along with the variable content of biogenic amines, suggests the need for increased attention to hygienic conditions during Njeguški cheese production. Significant variability was observed in humidity (ranging from 38.37 to 45.58 %), salt content (ranging from 0.70 to 1.78 %), proteins content (ranging from 21.42 to 25.08 %), ash content (ranging from 2.97 to 4.05 %), hardness, springiness, and color among samples from different producers. Gas chromatography-mass spectrometry analysis showed a well-defined and complex volatilome profile of the Njeguški cheese, with alcohols (ethanol, isoamyl alcohol, phenetyl alcol), esters and acetates (ethyl acetate, ethyl butanoate, isoamyl acetate), ketones (acetoin, 2-butanone), and acids (acetic, butanoic, hexanoic acids) being the main chemical groups involved in aroma formation. This research will provide new insights into the still poorly explored identity of Njeguški cheese, thus serving as a first baseline for future studies aimed at protecting its tradition.

Optoelectronic Properties of Triply Twisted Möbius Carbon Nanobelt and the Design of Its Isomeric Nanomaterials

The triply twisted Möbius carbon nanobelt (TMCNB) possesses an extremely distinctive geometric and electronic structure and therefore is anticipated to demonstrate outstanding optical properties. In this paper, through integrating quantum chemical calculations and wave function analysis approaches, in-depth studies are conducted on the one-photon absorption (OPA) and two-photon absorption (TPA) characteristics, aromaticity, and circular dichroism of the TMCNB. Inspired by this structure, we further deform it to construct a novel structure, MCNB2, and verify the stability of this structure, thereby confirming its rationality. Since variations in structure will result in dissimilar optical properties, we also undertake theoretical analyses on the absorption properties and circular dichroism of MCNB2. The outcomes of this study offer a significant theoretical foundation for the design and construction of chiral optoelectronic materials.

Breast Cancer-Related Chemical Exposures in Firefighters.

To fill a research gap on firefighter exposures and breast cancer risk, and guide exposure reduction, we aimed to identify firefighter occupational exposures linked to breast cancer. We conducted a systematic search and review to identify firefighter chemical exposures and then identified the subset that was associated with breast cancer. To do this, we compared the firefighter exposures with chemicals that have been shown to increase breast cancer risk in epidemiological studies or increase mammary gland tumors in experimental toxicology studies. For each exposure, we assigned a strength of evidence for the association with firefighter occupation and for the association with breast cancer risk. We identified twelve chemicals or chemical groups that were both linked to breast cancer and were firefighter occupational exposures, including polycyclic aromatic hydrocarbons, volatile aromatics, per- and polyfluoroalkyl substances, persistent organohalogens, and halogenated organophosphate flame retardants. Many of these were found at elevated levels in firefighting environments and were statistically significantly higher in firefighters after firefighting or when compared to the general population. Common exposure sources included combustion byproducts, diesel fuel and exhaust, firefighting foams, and flame retardants. Our findings highlight breast-cancer-related chemical exposures in the firefighting profession to guide equitable worker's compensation policies and exposure reduction.

Preparation and Characterization of Hydroxylated Recombinant Collagen by Incorporating Proline and Hydroxyproline in Proline-Deficient Escherichia coli.

Collagen possesses distinctive chemical properties and biological functions due to its unique triple helix structure. However, recombinant collagen expressed in Escherichia coli without post-translational modifications such as hydroxylation lacks full function since hydroxylation is considered to be critical to the stability of the collagen triple-helix at body temperature. Here, a proline-deficient E. coli strain was constructed and employed to prepare hydroxylated recombinant collagens by incorporating proline (Pro) and hydroxyproline (Hyp) from the culture medium. By controlling the ratio of Pro to Hyp in the culture medium, collagen with different degrees of hydroxylation (0-88%) can be obtained. When the ratio of Pro and Hyp was adjusted to 12:8 mM, the proline hydroxylation rate of recombinant human collagen (rhCol, 55 kDa) ranged from 40-50%, which was also the degree of natural collagen. After proline hydroxylation, both the thermal stability and cell binding of rhCol were significantly enhanced. Notably, when the hydroxylation rate approached that of native human collagen (40-50%), the improvements were most pronounced. Moreover, the cell binding of rhCol with a hydroxylation rate of 43% increased by 29%, and the melting temperature (Tm) rose by 5 °C compared to the non-hydroxylated rhCol. The system achieved a yield of 1.186 g/L of rhCol by batch-fed in a 7 L fermenter. This innovative technology is expected to drive the development and application of collagen-related biomaterials with significant application value in the fields of tissue engineering, regenerative medicine, and biopharmaceuticals.

Development of sustainable flame-retardant bio-based hydrogel composites from hemp/wool nonwovens with chitosan-banana sap hydrogel

Flame retardant (FR) finishing is crucial for developing protective textiles, traditionally relying on halogen, phosphorus, and phosphorus-nitrogen chemistries, which have limitations like toxicity and fabric stiffening. Innovative approaches such as nanotechnology, plasma treatments, and natural resource-based finishes are being explored to achieve sustainable FR textiles. This study presents the development and comprehensive characterization of hydrogel composites made from nonwoven fabrics composed of various hemp/wool blends (70/30, 80/20, and 90/10). The nonwoven fabrics were treated with a chitosan hydrogel incorporating banana sap to enhance their properties. Scanning electron microscope (SEM) examined the surface morphology and structural integrity of the composites, while Fourier transform infrared spectroscopy (FTIR) identified chemical interactions and functional groups. Differential scanning calorimeter (DSC) revealed thermal properties, water absorbency tests demonstrated hydrophilicity, mechanical testing assessed tensile strength, and vertical flammability tests evaluated fire resistance. SEM and FTIR revealed a successful coating of chitosan hydrogel with banana sap inclusions onto the hemp/wool nonwoven fabric, forming a composite structure. DSC analysis suggests higher chitosan content and hemp fiber ratio (like 70/30) lead to increased thermal stability of hydrogel composites. Higher chitosan concentrations in the hydrogel significantly improve the flame-retardant properties of hemp/wool nonwoven fabrics by reducing char length and enhancing protective char layer formation, with banana sap further promoting charring. These results indicate that the developed composite can be effectively used in flame-retardant textiles.

Advancement in Soft Hydrogel Grippers: Comprehensive Insights into Materials, Fabrication Strategies, Grasping Mechanism, and Applications.

Soft hydrogel grippers have attracted considerable attention due to their flexible/elastic bodies, stimuli-responsive grasping and releasing capacity, and novel applications in specific task fields. To create soft hydrogel grippers with robust grasping of various types of objects, high load capability, fast grab response, and long-time service life, researchers delve deeper into hydrogel materials, fabrication strategies, and underlying actuation mechanisms. This article provides a systematic overview of hydrogel materials used in soft grippers, focusing on materials composition, chemical functional groups, and characteristics and the strategies for integrating these responsive hydrogel materials into soft grippers, including one-step polymerization, additive manufacturing, and structural modification are reviewed in detail. Moreover, ongoing research about actuating mechanisms (e.g., thermal/electrical/magnetic/chemical) and grasping applications of soft hydrogel grippers is summarized. Some remaining challenges and future perspectives in soft hydrogel grippers are also provided. This work highlights the recent advances of soft hydrogel grippers, which provides useful insights into the development of the new generation of functional soft hydrogel grippers.

Rational analysis of hydrogen bonding interaction in phenazine, 2-hydroxynaphthalene (1:1) cocrystal: from molecular modeling to photophysical properties.

Organic cocrystals have a wide range of applications in the field of optics due to their photo responsive property. We present here a newly synthesized phenazine 2-hydroxynaphthalene (1:1) cocrystal, its structural and theoretical calculations which tend to the nonlinear optical property. In the crystal structure of the title cocrystal, the phenazine and 2-hydroxynaphthalene molecules from one- and two-dimensional supramolecular frameworks via O‒H…N hydrogen bonds and C‒H…N, C‒H…π interaction, respectively. The phenazine molecules from an infinite off-set stacking through π…π interactionin the three-dimensional molecular packing of the title cocrystal. The contribution of intermolecular interaction in the three-dimensional molecular packing and the interaction energy calculation is studied by the Hirshfeld surface analysis. The molecular geometry retrieved from the experimental X-ray diffraction analysis is in good agreement with the theoretically calculated parameters. Further, the molecular electrostatic potential (MEP) and frontier molecular orbital (FMO) analysis have been carried out to study the charge distribution and molecular reactive mechanism. Third-order nonlinear optical property of the cocrystals has been analyzed by Z-scan measurements. The determined nonlinear optical absorption coefficient value 6.442 × 10-05 (m/W) and the nonlinear refractive index value - 5.535 × 10-2 (m/W) suggest that the crystalline solid can be a good choice of potential nonlinear optical material. The crystal structures of phenazine 2-hydroxynaphthalene cocrystal was solved by direct methods procedure using SHELXS program and refined by full-matrix least square procedure on F2 using SHELXL-2018 program on Olex2 software. The computational calculation has been carried out using DFT/B3LYP quantum chemical function with triple zeta 6-311 + + basis set in the ground state molecular stability using Gaussian 09W program suite. The Hirshfeld surface analysis mapping, associated 2D fingerprint plot, and intermolecular molecular interaction energy calculations were carried out using CrystalExplorer (version 21.5) software.

In Situ Functionalization of Polar Polythiophene-Based Organic Electrochemical Transistor to Interface In Vitro Models.

Organic mixed ionic-electronic conductors are promising materials for interfacing and monitoring biological systems, with the aim of overcoming current challenges based on the mismatch between biological materials and convectional inorganic conductors. The conjugated polymer/polyelectrolyte complex poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT/PSS) is, up to date, the most widely used polymer for in vitro or in vivo measurements in the field of organic bioelectronics. However, PEDOT/PSS organic electrochemical transistors (OECTs) are limited by depletion mode operation and lack chemical groups that enable synthetic modifications for biointerfacing. Recently introduced thiophene-based polymers with oligoether side chains can operate in accumulation mode, and their chemical structure can be tuned during synthesis, for example, by the introduction of hydroxylated side chains. Here, we introduce a new thiophene-based conjugated polymer, p(g42T-T)-8% OH, where 8% of the glycol side chains are functionalized with a hydroxyl group. We report for the first time the compatibility of conjugated polymers containing ethylene glycol side chains in direct contact with cells. The additional hydroxyl group allows covalent modification of the surface of polymer films, enabling fine-tuning of the surface interaction properties of p(g42T-T)-8% OH with biological materials, either hindering or promoting cell adhesion. We further use p(g42T-T)-8% OH to fabricate the OECTs and demonstrate for the first time the monitoring of epithelial barrier formation of Caco-2 cells in vitro using accumulation mode OECTs. The conjugated polymer p(g42T-T)-8% OH allows organic-electronic-based materials to be easily modified and optimized to interface and monitor biological systems.

Synthesis and characterization of the dental adhesive monomer 10-MDP

Many studies have demonstrated the excellent performance of 10-MDP (10-methacryloyloxydecyl dihydrogen phosphate) as a functional monomer for dental adhesive materials and as a primer for ceramic surfaces. Although adhesive performance is affected by the purity level of 10-MDP, this parameter is rarely described, and possible byproducts have been suggested in the literature, but have not been identified to date. The present study aims to present an accessible 10-MDP synthesis strategy with easily handled reagents and address the characterization challenges, especially in identifying byproducts. 10-MDP was synthesized from 10-hydroxydecyl methacrylate and phosphorus pentoxide in acetone. The final product was characterized by nuclear magnetic resonance (NMR), infrared spectroscopy (FTIR) and mass spectrometry MALDITOF/TOF. The main chemical groups associated with 10-MDP were identified by 1H, 31P, and 13C NMR analyses. Only mass spectrometry analyses (MALDITOF/TOF) could identify the presence of dimers as byproducts. Its proposed chemical structure indicates that the dimers were formed by the reaction between the phosphate ester groups and others formed by the reaction of the methacrylic group of 10-MDP molecules. Careful adjustment of the synthesis conditions to reduce the formation of these byproducts is also described. The results indicate that the characterization of 10-MDP batches as raw materials is an important task because, depending on the byproduct present, its ability to polymerize or acid etching capacity may be compromised.

Evaluation of a New In Chemico Skin Corrosion Test

The purpose of this study is to evaluate a novel macromolecular test method for the identification of dermal corrosives. The simple in chemico test procedure involves allowing the material to be tested to interact with a skin biomarker for corrosivity and then adding a detection reagent. The corrosivity of the test substance is predicted based on the measured macromolecular damage, which results in reduced optical density of the detection reagent as compared with controls. This study aims to determine if such an extremely simple, cell-free test method can accurately identify dermal corrosives. To determine predictivity and repeatability, we tested 60 chemicals (30 in vivo dermal corrosives and 30 in vivo dermal noncorrosives; all tested in triplicate) representative of a broad range of chemical classes, functional groups, mixtures, and levels of toxicity. Validation results indicate the GHS multicategory and packing group assignment accuracy is on par with that of the Reconstructed Human Epidermis test method and the Membrane Barrier test method and for the global identification of corrosives, the method has a considerably higher accuracy (98 % vs. ∼80 %).

Characterization of water states and pore size distribution in Beijing poplar using nuclear magnetic resonance techniques

ABSTRACT This study employs nuclear magnetic resonance (NMR) techniques to elucidate the water states and pore size distribution within Beijing poplar (Populus beijingensis W. Y. Hsu) across various temperatures. By analyzing the variation in moisture content (MC) at different freezing temperatures, the proportion and distribution of cell wall pores were determined using the NMR Cryoporometry (NMR-C) method. The results show approximately 60% of the pores in both the heartwood (HW) and sapwood (SW) of Beijing poplar have diameters were 1.5 nm, while the proportion of pores with diameters greater than 4.6 nm was less than 10%. Moreover, the MC of both more freely bound water (C-water) and OH bound water (B-water) is observed to decrease exponentially with decreasing temperature. B-water in Beijing poplar is found to maintain a higher MC than C-water across the temperature range from −3 to −60°C, indicating greater resistance to freezing. The findings of this study contribute to a comprehensive understanding of water states in Beijing poplar. Also the pore size distribution of Beijing poplar provides reference data for the selection of wood chemical modification groups.

Construction of electrochemical immunosensor from MXene/multi-walled carbon nanotubes/gold nanoparticles for specific detection of carcinoembryonic antigen.

With the advancement of nanotechnology, various types of nanomaterials have been integrated into electrochemical immunoelectrodes to enhance their performance. Among these, MXene stands out as a promising candidate due to its high electron transfer capacity and abundant surface chemical groups. However, the improvement in electrode performance is often hindered by the self-restacking and agglomeration of MXene. To address this issue, multi-walled carbon nanotubes (MWCNTs) were selected to form composites with MXene. Subsequently, a label-free immunosensor, BSA/Ab/AuNPs/MXene-MWCNTs-Nafion/ITO, was fabricated for specific detection of carcinoembryonic antigen (CEA), a widely used tumor marker. The results demonstrated that the incorporation of MWCNTs can effectively prevent the self-stacking of MXene. Moreover, the composites enhanced the loading of gold nanoparticles (AuNPs) to connect the antibodies, thereby improving electronic transmission signals and sensitivity. The sensor exhibited excellent analytical performance towards CEA with a wide linear range (0.050 to 200ngmL-1) and a low limit of detection of 0.015ngmL-1 (S/N = 3). The possibility of it being applied in clinical trials was verified by using ELISA and differential pulse voltammetry (DPV) assays to detect CEA in serum samples. The recoveries ranged from 95.34 to 102.09% with relative standard deviations (RSDs) below 5.00%. Furthermore, the sensor displayed satisfactory selectivity, repeatability, and stability. We hope the findings highlight promising prospects for advanced immunosensor development and alternative strategies in cancer diagnosis.

Development and Implementation of an Algorithm for Predicting the Intensity of Sorption of Hazardous Gaseous Materials

An algorithm for predicting the intensity of sorption of gaseous materials released into the atmosphere as a result of an accident is proposed. The algorithm consists of three hierarchical levels: monitoring the parameters of gaseous material emission, predicting the consequences of gaseous material emission before and after sorption, and making a management decision. The first hierarchical level includes 4 blocks: obtaining information from the chemical reconnaissance group and the facility representative on the type, amount of hazardous gaseous materials, release intensity and scale of the accident; obtaining information from the hydrometeorological service on temperature, atmospheric pressure, wind direction and speed in the accident area; processing the information received; information on the availability of forces and means for sorption of hazardous gaseous materials. The second hierarchical level also includes 4 blocks: readiness of forces and means for sorption of hazardous gaseous materials; calculation with sorption; calculation without sorption; determination of the boundaries of the chemical damage zone according to the established criteria. At the third hierarchical level, there is 1 block: making a management decision. The software implementation of the proposed algorithm was carried out. The use of the developed algorithm and its software implementation will increase the speed and accuracy of predicting the consequences of the release of hazardous gaseous materials in an accident.